This invention relates generally to food products, and more particularly to an intermediate moisture, shelf stable pet food having a free gravy.
Pet foods are generally classified into one of three groups, depending upon the method of manufacture and, particularly, the moisture content of the final product. Dry pet foods, having less than about 12% total water content, are typically prepared from farinaceous base materials, with additions of proteinaceous materials for nutritional purposes. Dry pet foods are microbiologically stable without refrigeration, primarily because the very low moisture contents will not support microbiological growth. While such foods are convenient in that they may be stored in a sack at room temperatures and exposed to the atmosphere, they are the least palatable of the pet foods and have the lowest perceived desirability for the purchaser of the pet food.
At the high end of the moisture scale are moist pet foods, usually having more than about 60% water content. Moist pet foods are typically prepared from meat, meat by-products, poultry, poultry by-products, and fish and fish by-products. Further, because of the high water content such pet foods must be sterilized and preserved by techniques such as canning to avoid microbiological growth prior to consumption by the animal. Once the can is opened, the pet foods must be consumed relatively quickly to avoid spoilage.
Semi-moist pet foods have an intermediate amount of from about 15% to about 40% total water content, and are formulated so as to present an attractive compromise between dry and moist pet foods. The semi-moist pet foods are more stable than moist pet foods, and typically more palatable to the animal and attractive to the purchaser than dry pet foods. Semi-moist pet foods, are familiar to most pet owners as being provided as single servings packaged in a foil or film pouch. Such pouches may be conveniently stored at room temperature for extended periods.
Semi-moist pet foods are often prepared by extrusion of formulations based upon mixtures of farinaceous and proteinaceous ingredients, with addition of water, perservatives, flavorants and colorants. See, for example U.S. Pat. No. 3,202,514. The semi-moist pieces may be colored and processed to simulate meat, as, for example, strands formed into hamburger-like patties.
Semi-moist pet foods usually have a pliable, plastic feel and texture, and are essentially dry to the touch. Although water is present in an amount of about 15% to about 40% by weight, the water is not visually evident on or in the pet foods. On the other hand, the presence of a visually evident liquid phase, termed herein a "free gravy," is particularly desirable. However, as yet there have been provided no semi-moist pet foods having a free gravy.
Shelf stable, intermediate moisture content human foods are known, wherein pieces of meat or vegetable are cooked or immersed in a low-water-content perservative liquid of low water activity. The liquid essentially dehydrates the meat or vegetable pieces, which have a high water activity, with the result that the final product has a net water activity sufficiently low to be microbiologically stable during storage. The cooking liquid may be packaged with the meat or vegetable pieces, or an additional liquid having a water activity essentially the same as the dehydrated piece may be added prior to packaging. Such approaches are not, however, suitable for the preparation of intermediate moisture pet foods. In the described approach for making human food, the starting material is a relatively expensive meat or vegetable piece, rather than the relatively inexpensive farinaceous and proteinaceous mixture that form the majority of the dry weight of semi-moist pet foods.
Accordingly, there has been a need for a semi-moist, shelf stable pet food having a free gravy, but whose solid pieces are prepared from conventional, relatively inexpensive, farinaceous and proteinaceous base materials. The present invention fulfills this need, and further provides related advantages.